1. Field of the Invention
The present invention relates to a chain drive for a saddle-ride type vehicle in which power of an engine is transmitted to a rear wheel through a drive chain.
2. Description of Related Art
In this type of saddle-ride type vehicle, it is known that the tension on a drive chain varies due to the impact when the vehicle travels on a rough road or accelerates/decelerates. Especially in saddle-ride type vehicles in which a rear wheel is supported by a body frame through a swing arm, the variations in tension of the drive chain coupled with the swing of the swing arm make the drive chain likely to move up and down largely. The large up-and-down movement of the drive chain during traveling of the vehicle makes the drive chain more likely to interfere with the surroundings.
Therefore, as a chain drive for saddle-ride type vehicles which addresses this problem, there is known a chain drive in which a guide member for restricting the movement of the drive chain is mounted to a body frame (for example, see JP-U No. H2-97187).
In the chain drive disclosed in JP-U No. H2-97187, the downwardly opening U-section guide member is fixed to the body frame above a front portion of a swing arm so as to restrict excessive upward displacement of the drive chain.
However, in the above-described chain drive, because the special U-section guide member is mounted to the body frame, the structure of the guide member is complicated and a special mounting portion designed for the guide member needs to be installed on the body frame, which is likely to cause an increase in production costs.